In general, a portable electronic device such as a cellular phone, a laptop computer, and a PDA is provided therein with a storage battery so that a user can use the portable electronic device while moving.
However, the portable electronic device is equipped with an additional charger to charge power into the storage battery. The charger is connected to a typical power supply to charge power into the storage battery by supplying charge current to the storage battery of the portable electronic device. Meanwhile, in order to allow the charger to supply the charge current to the storage battery of the portable electronic device, a charging main body constituting the charger must be electrically connected to the storage battery of the portable electronic device. In order to electrically connect the charging main body to the storage battery of the portable electronic device, in the case of a wired charger (contact-type charger), the charging main body and the portable electronic device or the storage battery separately include connectors. Accordingly, in order to charge power into the storage battery of the portable electronic device, the connector of the portable electronic device or the storage battery must be mutually connected to the connector of the charging main body.
However, in the contact-type charger having the charging body connected to the storage body or the portable electronic device through the connector, the connector protrudes to the outside, so that an outer appearance is not only degraded, but the connector is contaminated with external foreign matters so that connection failure occurs. In addition, the connector is shorted due to careless use the according to occasions, so that the storage battery may be fully discharged.
In order to solve the problem, a scheme of charging the energy of the charging main body into the storage body by electrically connecting the charging main body to the storage battery of the portable electronic device through a wireless (non-contact) scheme has been developed.
According to the wireless charging scheme, a primary circuit operating at a high frequency constitutes the charging main body, and a secondary circuit constitutes a side of the storage battery, that is, is provided in the portable electronic device or the storage battery, so that the current of the charging main body, that is, energy is supplied to the storage battery of the portable electronic device through the induction coupling. The wireless charging scheme employing the induction coupling has been already employed in several application fields (e.g., electric toothbrush or electric razor).
However, when the wireless charging scheme is applied to portable electronic devices such as a cellular phone, a portable MP3 player, a CD player, an MD player, a cassette tape player, a laptop computer, and a PDA, targets to be charged have various sizes and require various powers (charge capacity) for charging.
Accordingly, when wireless batteries mounted on various electronic devices are charged by using the wireless charger, the wireless charger properly realized based on the size and the capacity of a target to be charged must be used in order to increase the charging efficiency.
However, when a user uses a charger suitable for the charging of each wireless battery in order to charge the wireless batteries mounted on various electronic devices, the user must retain various kinds of wireless chargers. In addition, if necessary, the user must inconveniently look for a wireless charger suitable for each wireless battery to charge the wireless battery.
In addition, since a plurality of portable appliances having different sizes and different shapes cannot be simultaneously charged by using one charging main body, the space may not be easily utilized.